1//===- DWARFDie.cpp -------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "llvm/DebugInfo/DWARF/DWARFDie.h"
10#include "llvm/ADT/SmallPtrSet.h"
11#include "llvm/ADT/SmallSet.h"
12#include "llvm/ADT/StringRef.h"
13#include "llvm/BinaryFormat/Dwarf.h"
14#include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
15#include "llvm/DebugInfo/DWARF/DWARFContext.h"
16#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
17#include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
18#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
19#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
20#include "llvm/DebugInfo/DWARF/DWARFTypePrinter.h"
21#include "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
22#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
23#include "llvm/Object/ObjectFile.h"
24#include "llvm/Support/DataExtractor.h"
25#include "llvm/Support/Format.h"
26#include "llvm/Support/FormatVariadic.h"
27#include "llvm/Support/MathExtras.h"
28#include "llvm/Support/WithColor.h"
29#include "llvm/Support/raw_ostream.h"
30#include <cassert>
31#include <cinttypes>
32#include <cstdint>
33#include <string>
34#include <utility>
35
36using namespace llvm;
37using namespace dwarf;
38using namespace object;
39
40static void dumpApplePropertyAttribute(raw_ostream &OS, uint64_t Val) {
41  OS << " (";
42  do {
43    uint64_t Shift = llvm::countr_zero(Val);
44    assert(Shift < 64 && "undefined behavior");
45    uint64_t Bit = 1ULL << Shift;
46    auto PropName = ApplePropertyString(Bit);
47    if (!PropName.empty())
48      OS << PropName;
49    else
50      OS << format("DW_APPLE_PROPERTY_0x%" PRIx64, Bit);
51    if (!(Val ^= Bit))
52      break;
53    OS << ", ";
54  } while (true);
55  OS << ")";
56}
57
58static void dumpRanges(const DWARFObject &Obj, raw_ostream &OS,
59                       const DWARFAddressRangesVector &Ranges,
60                       unsigned AddressSize, unsigned Indent,
61                       const DIDumpOptions &DumpOpts) {
62  if (!DumpOpts.ShowAddresses)
63    return;
64
65  for (const DWARFAddressRange &R : Ranges) {
66    OS << '\n';
67    OS.indent(Indent);
68    R.dump(OS, AddressSize, DumpOpts, &Obj);
69  }
70}
71
72static void dumpLocationList(raw_ostream &OS, const DWARFFormValue &FormValue,
73                             DWARFUnit *U, unsigned Indent,
74                             DIDumpOptions DumpOpts) {
75  assert(FormValue.isFormClass(DWARFFormValue::FC_SectionOffset) &&
76         "bad FORM for location list");
77  DWARFContext &Ctx = U->getContext();
78  uint64_t Offset = *FormValue.getAsSectionOffset();
79
80  if (FormValue.getForm() == DW_FORM_loclistx) {
81    FormValue.dump(OS, DumpOpts);
82
83    if (auto LoclistOffset = U->getLoclistOffset(Offset))
84      Offset = *LoclistOffset;
85    else
86      return;
87  }
88  U->getLocationTable().dumpLocationList(
89      &Offset, OS, U->getBaseAddress(), Ctx.getDWARFObj(), U, DumpOpts, Indent);
90}
91
92static void dumpLocationExpr(raw_ostream &OS, const DWARFFormValue &FormValue,
93                             DWARFUnit *U, unsigned Indent,
94                             DIDumpOptions DumpOpts) {
95  assert((FormValue.isFormClass(DWARFFormValue::FC_Block) ||
96          FormValue.isFormClass(DWARFFormValue::FC_Exprloc)) &&
97         "bad FORM for location expression");
98  DWARFContext &Ctx = U->getContext();
99  ArrayRef<uint8_t> Expr = *FormValue.getAsBlock();
100  DataExtractor Data(StringRef((const char *)Expr.data(), Expr.size()),
101                     Ctx.isLittleEndian(), 0);
102  DWARFExpression(Data, U->getAddressByteSize(), U->getFormParams().Format)
103      .print(OS, DumpOpts, U);
104}
105
106static DWARFDie resolveReferencedType(DWARFDie D, DWARFFormValue F) {
107  return D.getAttributeValueAsReferencedDie(F).resolveTypeUnitReference();
108}
109
110static void dumpAttribute(raw_ostream &OS, const DWARFDie &Die,
111                          const DWARFAttribute &AttrValue, unsigned Indent,
112                          DIDumpOptions DumpOpts) {
113  if (!Die.isValid())
114    return;
115  const char BaseIndent[] = "            ";
116  OS << BaseIndent;
117  OS.indent(Indent + 2);
118  dwarf::Attribute Attr = AttrValue.Attr;
119  WithColor(OS, HighlightColor::Attribute) << formatv("{0}", Attr);
120
121  dwarf::Form Form = AttrValue.Value.getForm();
122  if (DumpOpts.Verbose || DumpOpts.ShowForm)
123    OS << formatv(" [{0}]", Form);
124
125  DWARFUnit *U = Die.getDwarfUnit();
126  const DWARFFormValue &FormValue = AttrValue.Value;
127
128  OS << "\t(";
129
130  StringRef Name;
131  std::string File;
132  auto Color = HighlightColor::Enumerator;
133  if (Attr == DW_AT_decl_file || Attr == DW_AT_call_file) {
134    Color = HighlightColor::String;
135    if (const auto *LT = U->getContext().getLineTableForUnit(U)) {
136      if (std::optional<uint64_t> Val = FormValue.getAsUnsignedConstant()) {
137        if (LT->getFileNameByIndex(
138                *Val, U->getCompilationDir(),
139                DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath,
140                File)) {
141          File = '"' + File + '"';
142          Name = File;
143        }
144      }
145    }
146  } else if (std::optional<uint64_t> Val = FormValue.getAsUnsignedConstant())
147    Name = AttributeValueString(Attr, *Val);
148
149  if (!Name.empty())
150    WithColor(OS, Color) << Name;
151  else if (Attr == DW_AT_decl_line || Attr == DW_AT_decl_column ||
152           Attr == DW_AT_call_line || Attr == DW_AT_call_column) {
153    if (std::optional<uint64_t> Val = FormValue.getAsUnsignedConstant())
154      OS << *Val;
155    else
156      FormValue.dump(OS, DumpOpts);
157  } else if (Attr == DW_AT_low_pc &&
158             (FormValue.getAsAddress() ==
159              dwarf::computeTombstoneAddress(U->getAddressByteSize()))) {
160    if (DumpOpts.Verbose) {
161      FormValue.dump(OS, DumpOpts);
162      OS << " (";
163    }
164    OS << "dead code";
165    if (DumpOpts.Verbose)
166      OS << ')';
167  } else if (Attr == DW_AT_high_pc && !DumpOpts.ShowForm && !DumpOpts.Verbose &&
168             FormValue.getAsUnsignedConstant()) {
169    if (DumpOpts.ShowAddresses) {
170      // Print the actual address rather than the offset.
171      uint64_t LowPC, HighPC, Index;
172      if (Die.getLowAndHighPC(LowPC, HighPC, Index))
173        DWARFFormValue::dumpAddress(OS, U->getAddressByteSize(), HighPC);
174      else
175        FormValue.dump(OS, DumpOpts);
176    }
177  } else if (DWARFAttribute::mayHaveLocationList(Attr) &&
178             FormValue.isFormClass(DWARFFormValue::FC_SectionOffset))
179    dumpLocationList(OS, FormValue, U, sizeof(BaseIndent) + Indent + 4,
180                     DumpOpts);
181  else if (FormValue.isFormClass(DWARFFormValue::FC_Exprloc) ||
182           (DWARFAttribute::mayHaveLocationExpr(Attr) &&
183            FormValue.isFormClass(DWARFFormValue::FC_Block)))
184    dumpLocationExpr(OS, FormValue, U, sizeof(BaseIndent) + Indent + 4,
185                     DumpOpts);
186  else
187    FormValue.dump(OS, DumpOpts);
188
189  std::string Space = DumpOpts.ShowAddresses ? " " : "";
190
191  // We have dumped the attribute raw value. For some attributes
192  // having both the raw value and the pretty-printed value is
193  // interesting. These attributes are handled below.
194  if (Attr == DW_AT_specification || Attr == DW_AT_abstract_origin ||
195      Attr == DW_AT_call_origin) {
196    if (const char *Name =
197            Die.getAttributeValueAsReferencedDie(FormValue).getName(
198                DINameKind::LinkageName))
199      OS << Space << "\"" << Name << '\"';
200  } else if (Attr == DW_AT_type || Attr == DW_AT_containing_type) {
201    DWARFDie D = resolveReferencedType(Die, FormValue);
202    if (D && !D.isNULL()) {
203      OS << Space << "\"";
204      dumpTypeQualifiedName(D, OS);
205      OS << '"';
206    }
207  } else if (Attr == DW_AT_APPLE_property_attribute) {
208    if (std::optional<uint64_t> OptVal = FormValue.getAsUnsignedConstant())
209      dumpApplePropertyAttribute(OS, *OptVal);
210  } else if (Attr == DW_AT_ranges) {
211    const DWARFObject &Obj = Die.getDwarfUnit()->getContext().getDWARFObj();
212    // For DW_FORM_rnglistx we need to dump the offset separately, since
213    // we have only dumped the index so far.
214    if (FormValue.getForm() == DW_FORM_rnglistx)
215      if (auto RangeListOffset =
216              U->getRnglistOffset(*FormValue.getAsSectionOffset())) {
217        DWARFFormValue FV = DWARFFormValue::createFromUValue(
218            dwarf::DW_FORM_sec_offset, *RangeListOffset);
219        FV.dump(OS, DumpOpts);
220      }
221    if (auto RangesOrError = Die.getAddressRanges())
222      dumpRanges(Obj, OS, RangesOrError.get(), U->getAddressByteSize(),
223                 sizeof(BaseIndent) + Indent + 4, DumpOpts);
224    else
225      DumpOpts.RecoverableErrorHandler(createStringError(
226          errc::invalid_argument, "decoding address ranges: %s",
227          toString(RangesOrError.takeError()).c_str()));
228  }
229
230  OS << ")\n";
231}
232
233void DWARFDie::getFullName(raw_string_ostream &OS,
234                           std::string *OriginalFullName) const {
235  const char *NamePtr = getShortName();
236  if (!NamePtr)
237    return;
238  if (getTag() == DW_TAG_GNU_template_parameter_pack)
239    return;
240  dumpTypeUnqualifiedName(*this, OS, OriginalFullName);
241}
242
243bool DWARFDie::isSubprogramDIE() const { return getTag() == DW_TAG_subprogram; }
244
245bool DWARFDie::isSubroutineDIE() const {
246  auto Tag = getTag();
247  return Tag == DW_TAG_subprogram || Tag == DW_TAG_inlined_subroutine;
248}
249
250std::optional<DWARFFormValue> DWARFDie::find(dwarf::Attribute Attr) const {
251  if (!isValid())
252    return std::nullopt;
253  auto AbbrevDecl = getAbbreviationDeclarationPtr();
254  if (AbbrevDecl)
255    return AbbrevDecl->getAttributeValue(getOffset(), Attr, *U);
256  return std::nullopt;
257}
258
259std::optional<DWARFFormValue>
260DWARFDie::find(ArrayRef<dwarf::Attribute> Attrs) const {
261  if (!isValid())
262    return std::nullopt;
263  auto AbbrevDecl = getAbbreviationDeclarationPtr();
264  if (AbbrevDecl) {
265    for (auto Attr : Attrs) {
266      if (auto Value = AbbrevDecl->getAttributeValue(getOffset(), Attr, *U))
267        return Value;
268    }
269  }
270  return std::nullopt;
271}
272
273std::optional<DWARFFormValue>
274DWARFDie::findRecursively(ArrayRef<dwarf::Attribute> Attrs) const {
275  SmallVector<DWARFDie, 3> Worklist;
276  Worklist.push_back(*this);
277
278  // Keep track if DIEs already seen to prevent infinite recursion.
279  // Empirically we rarely see a depth of more than 3 when dealing with valid
280  // DWARF. This corresponds to following the DW_AT_abstract_origin and
281  // DW_AT_specification just once.
282  SmallSet<DWARFDie, 3> Seen;
283  Seen.insert(*this);
284
285  while (!Worklist.empty()) {
286    DWARFDie Die = Worklist.pop_back_val();
287
288    if (!Die.isValid())
289      continue;
290
291    if (auto Value = Die.find(Attrs))
292      return Value;
293
294    if (auto D = Die.getAttributeValueAsReferencedDie(DW_AT_abstract_origin))
295      if (Seen.insert(D).second)
296        Worklist.push_back(D);
297
298    if (auto D = Die.getAttributeValueAsReferencedDie(DW_AT_specification))
299      if (Seen.insert(D).second)
300        Worklist.push_back(D);
301  }
302
303  return std::nullopt;
304}
305
306DWARFDie
307DWARFDie::getAttributeValueAsReferencedDie(dwarf::Attribute Attr) const {
308  if (std::optional<DWARFFormValue> F = find(Attr))
309    return getAttributeValueAsReferencedDie(*F);
310  return DWARFDie();
311}
312
313DWARFDie
314DWARFDie::getAttributeValueAsReferencedDie(const DWARFFormValue &V) const {
315  DWARFDie Result;
316  if (auto SpecRef = V.getAsRelativeReference()) {
317    if (SpecRef->Unit)
318      Result = SpecRef->Unit->getDIEForOffset(SpecRef->Unit->getOffset() +
319                                              SpecRef->Offset);
320    else if (auto SpecUnit =
321                 U->getUnitVector().getUnitForOffset(SpecRef->Offset))
322      Result = SpecUnit->getDIEForOffset(SpecRef->Offset);
323  }
324  return Result;
325}
326
327DWARFDie DWARFDie::resolveTypeUnitReference() const {
328  if (auto Attr = find(DW_AT_signature)) {
329    if (std::optional<uint64_t> Sig = Attr->getAsReferenceUVal()) {
330      if (DWARFTypeUnit *TU = U->getContext().getTypeUnitForHash(
331              U->getVersion(), *Sig, U->isDWOUnit()))
332        return TU->getDIEForOffset(TU->getTypeOffset() + TU->getOffset());
333    }
334  }
335  return *this;
336}
337
338std::optional<uint64_t> DWARFDie::getRangesBaseAttribute() const {
339  return toSectionOffset(find({DW_AT_rnglists_base, DW_AT_GNU_ranges_base}));
340}
341
342std::optional<uint64_t> DWARFDie::getLocBaseAttribute() const {
343  return toSectionOffset(find(DW_AT_loclists_base));
344}
345
346std::optional<uint64_t> DWARFDie::getHighPC(uint64_t LowPC) const {
347  uint64_t Tombstone = dwarf::computeTombstoneAddress(U->getAddressByteSize());
348  if (LowPC == Tombstone)
349    return std::nullopt;
350  if (auto FormValue = find(DW_AT_high_pc)) {
351    if (auto Address = FormValue->getAsAddress()) {
352      // High PC is an address.
353      return Address;
354    }
355    if (auto Offset = FormValue->getAsUnsignedConstant()) {
356      // High PC is an offset from LowPC.
357      return LowPC + *Offset;
358    }
359  }
360  return std::nullopt;
361}
362
363bool DWARFDie::getLowAndHighPC(uint64_t &LowPC, uint64_t &HighPC,
364                               uint64_t &SectionIndex) const {
365  auto F = find(DW_AT_low_pc);
366  auto LowPcAddr = toSectionedAddress(F);
367  if (!LowPcAddr)
368    return false;
369  if (auto HighPcAddr = getHighPC(LowPcAddr->Address)) {
370    LowPC = LowPcAddr->Address;
371    HighPC = *HighPcAddr;
372    SectionIndex = LowPcAddr->SectionIndex;
373    return true;
374  }
375  return false;
376}
377
378Expected<DWARFAddressRangesVector> DWARFDie::getAddressRanges() const {
379  if (isNULL())
380    return DWARFAddressRangesVector();
381  // Single range specified by low/high PC.
382  uint64_t LowPC, HighPC, Index;
383  if (getLowAndHighPC(LowPC, HighPC, Index))
384    return DWARFAddressRangesVector{{LowPC, HighPC, Index}};
385
386  std::optional<DWARFFormValue> Value = find(DW_AT_ranges);
387  if (Value) {
388    if (Value->getForm() == DW_FORM_rnglistx)
389      return U->findRnglistFromIndex(*Value->getAsSectionOffset());
390    return U->findRnglistFromOffset(*Value->getAsSectionOffset());
391  }
392  return DWARFAddressRangesVector();
393}
394
395bool DWARFDie::addressRangeContainsAddress(const uint64_t Address) const {
396  auto RangesOrError = getAddressRanges();
397  if (!RangesOrError) {
398    llvm::consumeError(RangesOrError.takeError());
399    return false;
400  }
401
402  for (const auto &R : RangesOrError.get())
403    if (R.LowPC <= Address && Address < R.HighPC)
404      return true;
405  return false;
406}
407
408Expected<DWARFLocationExpressionsVector>
409DWARFDie::getLocations(dwarf::Attribute Attr) const {
410  std::optional<DWARFFormValue> Location = find(Attr);
411  if (!Location)
412    return createStringError(inconvertibleErrorCode(), "No %s",
413                             dwarf::AttributeString(Attr).data());
414
415  if (std::optional<uint64_t> Off = Location->getAsSectionOffset()) {
416    uint64_t Offset = *Off;
417
418    if (Location->getForm() == DW_FORM_loclistx) {
419      if (auto LoclistOffset = U->getLoclistOffset(Offset))
420        Offset = *LoclistOffset;
421      else
422        return createStringError(inconvertibleErrorCode(),
423                                 "Loclist table not found");
424    }
425    return U->findLoclistFromOffset(Offset);
426  }
427
428  if (std::optional<ArrayRef<uint8_t>> Expr = Location->getAsBlock()) {
429    return DWARFLocationExpressionsVector{
430        DWARFLocationExpression{std::nullopt, to_vector<4>(*Expr)}};
431  }
432
433  return createStringError(
434      inconvertibleErrorCode(), "Unsupported %s encoding: %s",
435      dwarf::AttributeString(Attr).data(),
436      dwarf::FormEncodingString(Location->getForm()).data());
437}
438
439const char *DWARFDie::getSubroutineName(DINameKind Kind) const {
440  if (!isSubroutineDIE())
441    return nullptr;
442  return getName(Kind);
443}
444
445const char *DWARFDie::getName(DINameKind Kind) const {
446  if (!isValid() || Kind == DINameKind::None)
447    return nullptr;
448  // Try to get mangled name only if it was asked for.
449  if (Kind == DINameKind::LinkageName) {
450    if (auto Name = getLinkageName())
451      return Name;
452  }
453  return getShortName();
454}
455
456const char *DWARFDie::getShortName() const {
457  if (!isValid())
458    return nullptr;
459
460  return dwarf::toString(findRecursively(dwarf::DW_AT_name), nullptr);
461}
462
463const char *DWARFDie::getLinkageName() const {
464  if (!isValid())
465    return nullptr;
466
467  return dwarf::toString(findRecursively({dwarf::DW_AT_MIPS_linkage_name,
468                                          dwarf::DW_AT_linkage_name}),
469                         nullptr);
470}
471
472uint64_t DWARFDie::getDeclLine() const {
473  return toUnsigned(findRecursively(DW_AT_decl_line), 0);
474}
475
476std::string
477DWARFDie::getDeclFile(DILineInfoSpecifier::FileLineInfoKind Kind) const {
478  if (auto FormValue = findRecursively(DW_AT_decl_file))
479    if (auto OptString = FormValue->getAsFile(Kind))
480      return *OptString;
481  return {};
482}
483
484void DWARFDie::getCallerFrame(uint32_t &CallFile, uint32_t &CallLine,
485                              uint32_t &CallColumn,
486                              uint32_t &CallDiscriminator) const {
487  CallFile = toUnsigned(find(DW_AT_call_file), 0);
488  CallLine = toUnsigned(find(DW_AT_call_line), 0);
489  CallColumn = toUnsigned(find(DW_AT_call_column), 0);
490  CallDiscriminator = toUnsigned(find(DW_AT_GNU_discriminator), 0);
491}
492
493static std::optional<uint64_t>
494getTypeSizeImpl(DWARFDie Die, uint64_t PointerSize,
495                SmallPtrSetImpl<const DWARFDebugInfoEntry *> &Visited) {
496  // Cycle detected?
497  if (!Visited.insert(Die.getDebugInfoEntry()).second)
498    return {};
499  if (auto SizeAttr = Die.find(DW_AT_byte_size))
500    if (std::optional<uint64_t> Size = SizeAttr->getAsUnsignedConstant())
501      return Size;
502
503  switch (Die.getTag()) {
504  case DW_TAG_pointer_type:
505  case DW_TAG_reference_type:
506  case DW_TAG_rvalue_reference_type:
507    return PointerSize;
508  case DW_TAG_ptr_to_member_type: {
509    if (DWARFDie BaseType = Die.getAttributeValueAsReferencedDie(DW_AT_type))
510      if (BaseType.getTag() == DW_TAG_subroutine_type)
511        return 2 * PointerSize;
512    return PointerSize;
513  }
514  case DW_TAG_const_type:
515  case DW_TAG_immutable_type:
516  case DW_TAG_volatile_type:
517  case DW_TAG_restrict_type:
518  case DW_TAG_typedef: {
519    if (DWARFDie BaseType = Die.getAttributeValueAsReferencedDie(DW_AT_type))
520      return getTypeSizeImpl(BaseType, PointerSize, Visited);
521    break;
522  }
523  case DW_TAG_array_type: {
524    DWARFDie BaseType = Die.getAttributeValueAsReferencedDie(DW_AT_type);
525    if (!BaseType)
526      return std::nullopt;
527    std::optional<uint64_t> BaseSize =
528        getTypeSizeImpl(BaseType, PointerSize, Visited);
529    if (!BaseSize)
530      return std::nullopt;
531    uint64_t Size = *BaseSize;
532    for (DWARFDie Child : Die) {
533      if (Child.getTag() != DW_TAG_subrange_type)
534        continue;
535
536      if (auto ElemCountAttr = Child.find(DW_AT_count))
537        if (std::optional<uint64_t> ElemCount =
538                ElemCountAttr->getAsUnsignedConstant())
539          Size *= *ElemCount;
540      if (auto UpperBoundAttr = Child.find(DW_AT_upper_bound))
541        if (std::optional<int64_t> UpperBound =
542                UpperBoundAttr->getAsSignedConstant()) {
543          int64_t LowerBound = 0;
544          if (auto LowerBoundAttr = Child.find(DW_AT_lower_bound))
545            LowerBound = LowerBoundAttr->getAsSignedConstant().value_or(0);
546          Size *= *UpperBound - LowerBound + 1;
547        }
548    }
549    return Size;
550  }
551  default:
552    if (DWARFDie BaseType = Die.getAttributeValueAsReferencedDie(DW_AT_type))
553      return getTypeSizeImpl(BaseType, PointerSize, Visited);
554    break;
555  }
556  return std::nullopt;
557}
558
559std::optional<uint64_t> DWARFDie::getTypeSize(uint64_t PointerSize) {
560  SmallPtrSet<const DWARFDebugInfoEntry *, 4> Visited;
561  return getTypeSizeImpl(*this, PointerSize, Visited);
562}
563
564/// Helper to dump a DIE with all of its parents, but no siblings.
565static unsigned dumpParentChain(DWARFDie Die, raw_ostream &OS, unsigned Indent,
566                                DIDumpOptions DumpOpts, unsigned Depth = 0) {
567  if (!Die)
568    return Indent;
569  if (DumpOpts.ParentRecurseDepth > 0 && Depth >= DumpOpts.ParentRecurseDepth)
570    return Indent;
571  Indent = dumpParentChain(Die.getParent(), OS, Indent, DumpOpts, Depth + 1);
572  Die.dump(OS, Indent, DumpOpts);
573  return Indent + 2;
574}
575
576void DWARFDie::dump(raw_ostream &OS, unsigned Indent,
577                    DIDumpOptions DumpOpts) const {
578  if (!isValid())
579    return;
580  DWARFDataExtractor debug_info_data = U->getDebugInfoExtractor();
581  const uint64_t Offset = getOffset();
582  uint64_t offset = Offset;
583  if (DumpOpts.ShowParents) {
584    DIDumpOptions ParentDumpOpts = DumpOpts;
585    ParentDumpOpts.ShowParents = false;
586    ParentDumpOpts.ShowChildren = false;
587    Indent = dumpParentChain(getParent(), OS, Indent, ParentDumpOpts);
588  }
589
590  if (debug_info_data.isValidOffset(offset)) {
591    uint32_t abbrCode = debug_info_data.getULEB128(&offset);
592    if (DumpOpts.ShowAddresses)
593      WithColor(OS, HighlightColor::Address).get()
594          << format("\n0x%8.8" PRIx64 ": ", Offset);
595
596    if (abbrCode) {
597      auto AbbrevDecl = getAbbreviationDeclarationPtr();
598      if (AbbrevDecl) {
599        WithColor(OS, HighlightColor::Tag).get().indent(Indent)
600            << formatv("{0}", getTag());
601        if (DumpOpts.Verbose) {
602          OS << format(" [%u] %c", abbrCode,
603                       AbbrevDecl->hasChildren() ? '*' : ' ');
604          if (std::optional<uint32_t> ParentIdx = Die->getParentIdx())
605            OS << format(" (0x%8.8" PRIx64 ")",
606                         U->getDIEAtIndex(*ParentIdx).getOffset());
607        }
608        OS << '\n';
609
610        // Dump all data in the DIE for the attributes.
611        for (const DWARFAttribute &AttrValue : attributes())
612          dumpAttribute(OS, *this, AttrValue, Indent, DumpOpts);
613
614        if (DumpOpts.ShowChildren && DumpOpts.ChildRecurseDepth > 0) {
615          DWARFDie Child = getFirstChild();
616          DumpOpts.ChildRecurseDepth--;
617          DIDumpOptions ChildDumpOpts = DumpOpts;
618          ChildDumpOpts.ShowParents = false;
619          while (Child) {
620            Child.dump(OS, Indent + 2, ChildDumpOpts);
621            Child = Child.getSibling();
622          }
623        }
624      } else {
625        OS << "Abbreviation code not found in 'debug_abbrev' class for code: "
626           << abbrCode << '\n';
627      }
628    } else {
629      OS.indent(Indent) << "NULL\n";
630    }
631  }
632}
633
634LLVM_DUMP_METHOD void DWARFDie::dump() const { dump(llvm::errs(), 0); }
635
636DWARFDie DWARFDie::getParent() const {
637  if (isValid())
638    return U->getParent(Die);
639  return DWARFDie();
640}
641
642DWARFDie DWARFDie::getSibling() const {
643  if (isValid())
644    return U->getSibling(Die);
645  return DWARFDie();
646}
647
648DWARFDie DWARFDie::getPreviousSibling() const {
649  if (isValid())
650    return U->getPreviousSibling(Die);
651  return DWARFDie();
652}
653
654DWARFDie DWARFDie::getFirstChild() const {
655  if (isValid())
656    return U->getFirstChild(Die);
657  return DWARFDie();
658}
659
660DWARFDie DWARFDie::getLastChild() const {
661  if (isValid())
662    return U->getLastChild(Die);
663  return DWARFDie();
664}
665
666iterator_range<DWARFDie::attribute_iterator> DWARFDie::attributes() const {
667  return make_range(attribute_iterator(*this, false),
668                    attribute_iterator(*this, true));
669}
670
671DWARFDie::attribute_iterator::attribute_iterator(DWARFDie D, bool End)
672    : Die(D), Index(0) {
673  auto AbbrDecl = Die.getAbbreviationDeclarationPtr();
674  assert(AbbrDecl && "Must have abbreviation declaration");
675  if (End) {
676    // This is the end iterator so we set the index to the attribute count.
677    Index = AbbrDecl->getNumAttributes();
678  } else {
679    // This is the begin iterator so we extract the value for this->Index.
680    AttrValue.Offset = D.getOffset() + AbbrDecl->getCodeByteSize();
681    updateForIndex(*AbbrDecl, 0);
682  }
683}
684
685void DWARFDie::attribute_iterator::updateForIndex(
686    const DWARFAbbreviationDeclaration &AbbrDecl, uint32_t I) {
687  Index = I;
688  // AbbrDecl must be valid before calling this function.
689  auto NumAttrs = AbbrDecl.getNumAttributes();
690  if (Index < NumAttrs) {
691    AttrValue.Attr = AbbrDecl.getAttrByIndex(Index);
692    // Add the previous byte size of any previous attribute value.
693    AttrValue.Offset += AttrValue.ByteSize;
694    uint64_t ParseOffset = AttrValue.Offset;
695    if (AbbrDecl.getAttrIsImplicitConstByIndex(Index))
696      AttrValue.Value = DWARFFormValue::createFromSValue(
697          AbbrDecl.getFormByIndex(Index),
698          AbbrDecl.getAttrImplicitConstValueByIndex(Index));
699    else {
700      auto U = Die.getDwarfUnit();
701      assert(U && "Die must have valid DWARF unit");
702      AttrValue.Value = DWARFFormValue::createFromUnit(
703          AbbrDecl.getFormByIndex(Index), U, &ParseOffset);
704    }
705    AttrValue.ByteSize = ParseOffset - AttrValue.Offset;
706  } else {
707    assert(Index == NumAttrs && "Indexes should be [0, NumAttrs) only");
708    AttrValue = {};
709  }
710}
711
712DWARFDie::attribute_iterator &DWARFDie::attribute_iterator::operator++() {
713  if (auto AbbrDecl = Die.getAbbreviationDeclarationPtr())
714    updateForIndex(*AbbrDecl, Index + 1);
715  return *this;
716}
717
718bool DWARFAttribute::mayHaveLocationList(dwarf::Attribute Attr) {
719  switch(Attr) {
720  case DW_AT_location:
721  case DW_AT_string_length:
722  case DW_AT_return_addr:
723  case DW_AT_data_member_location:
724  case DW_AT_frame_base:
725  case DW_AT_static_link:
726  case DW_AT_segment:
727  case DW_AT_use_location:
728  case DW_AT_vtable_elem_location:
729    return true;
730  default:
731    return false;
732  }
733}
734
735bool DWARFAttribute::mayHaveLocationExpr(dwarf::Attribute Attr) {
736  switch (Attr) {
737  // From the DWARF v5 specification.
738  case DW_AT_location:
739  case DW_AT_byte_size:
740  case DW_AT_bit_offset:
741  case DW_AT_bit_size:
742  case DW_AT_string_length:
743  case DW_AT_lower_bound:
744  case DW_AT_return_addr:
745  case DW_AT_bit_stride:
746  case DW_AT_upper_bound:
747  case DW_AT_count:
748  case DW_AT_data_member_location:
749  case DW_AT_frame_base:
750  case DW_AT_segment:
751  case DW_AT_static_link:
752  case DW_AT_use_location:
753  case DW_AT_vtable_elem_location:
754  case DW_AT_allocated:
755  case DW_AT_associated:
756  case DW_AT_data_location:
757  case DW_AT_byte_stride:
758  case DW_AT_rank:
759  case DW_AT_call_value:
760  case DW_AT_call_origin:
761  case DW_AT_call_target:
762  case DW_AT_call_target_clobbered:
763  case DW_AT_call_data_location:
764  case DW_AT_call_data_value:
765  // Extensions.
766  case DW_AT_GNU_call_site_value:
767  case DW_AT_GNU_call_site_target:
768    return true;
769  default:
770    return false;
771  }
772}
773
774namespace llvm {
775
776void dumpTypeQualifiedName(const DWARFDie &DIE, raw_ostream &OS) {
777  DWARFTypePrinter(OS).appendQualifiedName(DIE);
778}
779
780void dumpTypeUnqualifiedName(const DWARFDie &DIE, raw_ostream &OS,
781                             std::string *OriginalFullName) {
782  DWARFTypePrinter(OS).appendUnqualifiedName(DIE, OriginalFullName);
783}
784
785} // namespace llvm
786